Model 121 Programmable DC Current Source


The Model 121 programmable DC current source is a precision instrument suitable for bench-top use or panel-mounted operation in labs, test facilities, and manufacturing environments. It provides a low-noise, highly stable source of current up to 100 mA, with convenient manual selection through 13 pre-set output levels, each representing a ten-fold change in power when attached to a resistive load. A “user” setting allows the current output to be defined anywhere within the operating range of the unit, from 100 nA to 100 mA. 

Programmable operation is also possible via the instrument’s USB computer interface, through which the Model 121 can be commanded to output any desired current at any time. Thus, application-specific test currents can be driven from an external PC. 

The instrument operates at 5 VDC, and power is supplied by the external AC wall-mount supply provided with the standard Model 121. The supply will automatically conform to any AC line voltage ranging from 100 VAC to 240 VAC, 50 or 60 Hz.

Model 121 features

  • 7 decades of output current, selectable in 13 steps
  • Programmable current output, 100 nA to 100 mA
  • Low-noise output
  • Large 3-digit LED display
  • Simple user interface
  • Current reversal feature
  • USB interface enables integration with automated test systems
  • DIN panel-mountable package
  • Detachable output terminal block
  • CE mark certification



+44 (0)1372 378822


Technical Product Manager X-ray Systems & Optical Components
+44 (0)1372 378822


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Model 121 Specifications

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